Adding a junction box to existing EMT without cutting existing wires

[AffableCurmudgeon]

I know the answer is likely "No" but I will ask anyway.

I have an existing run of 1/2 inch EMT. Would like add another two pairs of THHN conductors (all within NEC fill limits for 1/2 inch EMT) for part of a new run. The new run will meet the exiting run at 90 degrees.

I would like to add a junction box to the existing EMT run where it would meet the new EMT run. There are two pairs of conductors in the existing EMT. I can always cut them and splice them in the junction box but wanted to see if there exists a mythical junction box that comes apart in two pieces and can be slipped over existing conductors if I cut off part of the existing EMT to make room for the junction box?

Like I said, I can always cut the existing wires, add the junction box and splice the existing wires in the junction box, but just checking.

Thanks.

 

[ard]

Mythical indeed.

I don't know- nobody can 'know' that something DOESNT exist. However the challenges are extreme for such a product- both in terms of engineering and construction, as well as installation (so how DO you get that 3.75 inches of EMT that you no longer need, off the wires???). Combined with the amazingly rare NEED for this with professionals....

Anyway, Wylie or NorCal will now post "Here you go- use these all the time"

 

[theoldwizard1]

Can do disconnect the existing wires from one end and then pull them back ?

 

[ard]

I guess I'll guess that the only time this would be a need is when you have reached the conductor count on the new, added box and dont want a splice to double the conductors?

Or you are out if wire nuts.

 

[AffableCurmudgeon]

Can do disconnect the existing wires from one end and then pull them back ?

I can, although easier to just splice as it is a long and crooked run to the next end.

It is not that I don't have a number of options, I was just interested if anyone as ever seen a splitting j-box.

 

[Syberia]

Not sure how you'd even do this - there's no way to remove a piece of EMT from the middle of a run wthout cutting/damaging the wires inside, and even if you did, you can't slip connectors onto the ends with the wires in the way, so you won't be able to secure it to the new box.

Best to tape a long string to whichever end of the run is easier to disconnect, pull it back through the conduit to the place you want to add the box, and put it back using the string. If you cut the wires in the middle and then add the box, you're not going to have enough slack to splice them back together...

 

[the gypsy]

I am thinking. Maybe if you install two boxes there may be a way. So try and follow my thought. If you can use a pipe cutter ( like a copper pipe cutter) make two cuts the width of the box then try to break (it is a safer alternative) or cut the piece with a dremel tool being careful not to go to deep. then locate another spot to install another box ( providing it is on the same wall with no curves or corners). Do the same on the other side now you have something to work with. move the now loose conduit to one side and cut the wire as long as you can now do the same on the other side and remove the conduit and the wire inside the conduit. and you can add the boxes and change out the wire between the 2 boxes with the appropriate length wire and conduit

Please turn off the power before you attempt this.
.

 

[wyliesdiesels]

Nothing i can think of.

And if u cut the wires mid run, u wont have enough to splice to.

Code requires 6" past box.

But u wont have even 1" unless there is slack somewhere....

 

[the gypsy]

Nothing i can think of.

And if u cut the wires mid run, u wont have enough to splice to.

Code requires 6" past box.

But u wont have even 1" unless there is slack somewhere....

This is why I suggested 2 cuts so he can replace the wire between the cuts to conform to the rules

 

[AffableCurmudgeon]

I am thinking. Maybe if you install two boxes there may be a way. So try and follow my thought. If you can use a pipe cutter ( like a copper pipe cutter) make two cuts the width of the box then try to break (it is a safer alternative) or cut the piece with a dremel tool being careful not to go to deep. then locate another spot to install another box ( providing it is on the same wall with no curves or corners). Do the same on the other side now you have something to work with. move the now loose conduit to one side and cut the wire as long as you can now do the same on the other side and remove the conduit and the wire inside the conduit. and you can add the boxes and change out the wire between the 2 boxes with the appropriate length wire and conduit

Please turn off the power before you attempt this.
.

That is a great idea! I will do just that. Thanks. The existing run is on the ceiling of the unfinished part of my basement. A copper tubing cutter will work great as i have plenty of room to go around the tube with it between the joists. Two boxes, with new pieces of conductors in between, will give me the slack I need.

But turning off the power, really? Do I have to do that? Just kidding. I only have one life and I value it tremendously.

Great idea, thanks again!

 

[the gypsy]

You are welcome. I am glad that it will work for you.

 

[the gypsy]

Please remember to deburr the inside of the conduit if needed.

 

[the gypsy]

Hello Ashamsi. I forgot to mention to mark your wires before you cut both sides, if they are not all different colors. Example if there are 2 whites and 2 black or any other variation.